Receivers generally include circuitry to perform auto-correlations and/or cross-correlations to determine whether an input signal has a desired property. For example, in wireless networks, such as wireless local area networks (WLANs) and broadband wireless access (BWA) networks, correlations are performed to identify special training signals. In code-division multiple access (CDMA) systems, correlations are performed in the rake receiver to identify and combine spread spectrum signal components. In radar and target-detection systems, correlations may be performed to identify radar-return signals.
In some situations, only the structure of the received signal is of interest, not its magnitude; therefore some conventional correlators generally perform an energy normalization process to eliminate the magnitude information for subsequent circuitry. This energy normalization process requires excess hardware and consumes power.
Thus, there are general needs for receivers that perform correlations without the need for energy normalization. There are also general needs for receivers that perform correlations that require less hardware and/or consume less energy.